There is known a rotor for a rotating electric machine including a rotor iron core having a shaft hole in which a shaft is press fitted for securing (See PTL 1, for example).
FIG. 1 is a cross-sectional view of a conventional rotor. A rotating electric machine includes a stator (not shown) and a rotor 300. The rotor 300 includes a rotor iron core 400 and a shaft 500. The rotor iron core 400 is made of a stack of flat rolled magnetic steel sheets.
The rotor iron core 400 has a shaft hole 410 at the center. The shaft 500 is press fitted in the shaft hole. The rotor iron core 400 has a plurality of lightening holes 450 for reducing moment of inertia. The rotor iron core 400 includes an inner area 420 surrounding the shaft hole 410, the lightening holes 450 surrounding the inner area 420, an outer area 440 surrounding the lightening holes 450, and a plurality of ribs 430 connecting the inner area 420 and the outer area 440.